The invention concerns a device for making the gathering of logging waste quicker and for compacting of logging waste.
By means of the device, the gathering is carried out even from a thin layer by means of a dragging movement.
In the prior art, logging waste is gathered by means of a freely suspended grab. Since the material is widely spread as a relatively thin layer, a number of grasping operations must be carried out by means of the grab by always lifting the load to a new location in order to add material to the grasp load.
When working takes place with the present-day equipment, drawbacks include the slow working when material is gathered into the grab, because it is necessary to lift heaps one onto the other so that a full load can be gathered for lifting onto the vehicle. Nor is it possible to achieve complete gathering of logging waste by means of the grasping method.
Since, by means of the prior-art grabs, it is almost not at all possible to affect the shape of the bundle, the directions of the logging waste in the grab remain highly different, and this has the consequence that the bundle in the grab remains loose because of the logging waste material placed crosswise. This results in a number of drawbacks; less material can be fitted in a vehicle load, and the further handling to the storage heap and from it to the chipper or to a vehicle for long-distance transportation is slower and, owing to the loose compacting, less economical. With the prior-art grabs, the bundle s already contained in the load cannot be compacted.
With respect to the prior art related to the present invention, reference is made to the patent publications U.S. Pat. No. 4,017,114, U.S. Pat. No. 4,353,424, and U.S. Pat. No. 3,802,731.
By means of the device in accordance with the present invention, a decisive improvement is provided in respect of the drawbacks mentioned above. In view of achieving this, the device in accordance with the invention includes an arm connected to an arm of a crane by an articulated joint, the arm being pivotable, by means of a power unit, around the articulated joint against a backup plate so as to incline the grab into a dragging position.
It can be considered to be the most important advantage of the invention that the working becomes essentially quicker as a thin layer of logging waste can be gathered, from the area of a number of grasping bundles, by means of one dragging movement by dragging along the ground surface to make a compact bundle in the grab. Further, the dragging movement has the effect that the branches and tree tops included in the logging waste are shifted into a substantially parallel oblong bundle. Good compacting of the bundle is also promoted by the fact that, being parallel, the material is compacted into a smaller volume than the space required if the material were lifted by the grab out of crosswise material of logging waste. Filling of the grab by means of a dragging movement also has the effect that the bundle becomes larger, because the tree tops and branches included in the bundle also attract material from a wider area than can be gathered by means of a grasping movement alone. Gathering by means of a dragging movement has also the effect that the logging waste can be recovered more completely. The working method can be compared with raking up.
An oblong compact bundle for the grab produced by means of a dragging movement has also the effect that more material can be fitted in the load, and when the load is unloaded to a storage heap, the logging waste is placed in the heap as parallel, so that it can be fed into the chipper more readily and more quickly, whereby the output of the chipper can be increased, or the waste can be loaded onto a vehicle for long-distance transportation, in which case the compactness of the bundles that are loaded has an essential significance for the economy of transportation, because the weight of logging waste is low in relation to its volume.
Further, the device can be provided with pivotal arms, which have two functions; when pivoted to the side, they operate during a dragging movement so as to keep the device at a correct level so that the arms of the device are not lowered below the ground level, and when the arms have been pivoted downwards, by their means, when the arms are inserted between bundles that have been loaded earlier, by means of a grab opening movement, the bundles can be compacted against the sides of the cargo space in order to provide space for the bundle that is being lowered from the grab. This compacting is possible In the case of bundles of oblong shape only, which bundles have been fitted as parallel and which can be produced by means of the device in accordance with the present invention and by means of the working method applied in connection with the device.
Thus, by means of the device in accordance with the invention, in a number of stages, compacting is achieved so as to make a loose material economically more favorable in view of loading and transportation.
In the following, the invention will be described in detail with reference to the accompanying drawing.